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Abstract  

Radioisotope induced X-ray fluorescence analysis is a rather simple and convenient method for investigating ashed plant material. In order to reduce matrix effects, thin samples (2 mg/cm2) are analyzed to obtain a reasonable compromise between maximum sensitivity and the lowest possible absorption effects. Concentrations are determined by standard addition method. A precision of 6–8% can be achieved. As an application, analytical results are given for whole grains of several sorts of wheat.

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Summary  

The adsorption kinetics of strontium ion was studied on seven natural clay samples with radioactive tracer method. The kinetic curves were determined and the kinetic data were evaluated by forms of first-rate kinetic equations with different terms, generally used for adsorption of ions of low concentration. The adsorption process was reduced to two steps. Film diffusion and participle diffusion were found in the case of five samples. Gel diffusion, film diffusion and participle diffusion were found in the case of the other two samples. The presence of significant amount of cristobalite can explain the gel phase in these two samples. The rate coefficients of steps were calculated from the kinetic curves.

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Abstract  

A measuring technique based on the alpha particles being released from the10B(n, α) nuclear reaction and using the time-of-flight technique at a periodically pulsing reactor was developed. Non-destructive determination for the range distribution of boron impurities in ion-implanted silicon have been performed. Projected ranges obtained in the energy region 20–80 keV are compared to calculated results and to other experiments. Examples are shown for some typical boron distributions before and after annealing the sample.

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Journal of Radioanalytical and Nuclear Chemistry
Authors: E. Kuzmann, S. Stichleutner, Z. Homonnay, A. Vértes, A. Paszternák, F. Nagy, I. Felhősi, G. Pető, J. Telegdi, and E. Kálmán

Abstract  

Thin films prepared by vacuum evaporation of 57Fe and subsequent low energy ion implantation were investigated by conversion electron Mössbauer spectroscopy and AFM measurements. A sextet with Mössbauer parameters of δ = 0.1 mm/s and B = 26 T appearing in the CEM spectra was identified as amorphous iron. Passivation and phosphonation of the thin films revealed the high affinity of amorphous iron in chemical reactions.

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